April 15, 1920] 



NATURE 



201 



The Nitrogen Problem : By-productsJ 



IT is surely high time that we, as a nation, 

 were more fully alive to the necessity of a 

 complete investigation of the recovery of by- 

 products, and that not merely in connection with 

 nitrogen products. There is still too much of 

 the feeling — one comes across it quite frequently 

 — that so-called waste products form a recognised 

 loss in any process. The investigation of the 

 treatment of any waste product is not looked 

 upon as the work of the person engaged in the 

 specific manufacture from which that waste pro- 

 duct is obtained. Competition becomes keener 

 as the years pass, and if our position is to be 

 retained by-products must be recovered in all 

 cases where such recovery can be economically 

 effected. A waste product may even become the 

 starting point of a new industry. The detailed 

 investigation of the position as regards nitrogen 

 by-products manufacture comes as a very 

 welcome record and as a much-needed indicator 

 of the forward path. 



The world's ammonia production, in terms of 

 sulphate, advanced between the years 1903 and 

 1913 from 540,200 long tons to 1,389,790, an 

 increase of more than 150 per cent. The chief 

 producers were Germany, the United Kingdom, 

 and the United States, who were respectively re- 

 sponsible in 1913 for 39, 31, and \2\ per cent, of 

 the total production. The essential sources are 

 gas-works, coke-ovens, gas-producers, shale- 

 works, iron-works, and bone, etc., carbonising 

 works. 



In the years 191 1 and 1913 the coke-oven 

 industry was responsible for 84 and 86 per cent, 

 respectively of the German production, in 1913 

 for 78 per cent, of the United States production, 

 and in 191 1 and 1913 for 27 and 30 per cent, of 

 the United Kingdom production. The United 

 Kingdom production rose from 233,664 long tons 

 in 1903 to 432,618 in 1913, of which, in 1903, 

 gas-works provided 149,489 long tons, or 64 per 

 cent, of the total, which steadily increased to 

 182,180, or 42 per cent, of the total. Coke-ovens 

 in the United Kingdom provided in 1903 only 

 17,438 tons, or barely 7^ per cent., but con- 

 tinual increase brought up the amount by 191 3 

 to 133,816 tons, practically 31 per cent, of the 

 production of the country. Iron-works during this 

 period retained a steady output of 19,000 to 

 20,000 tons, shale-works production increased 

 gradually from 37,353 to 63,061 tons, and that of 

 producer-gas, bone, etc., carbonising works from 

 10,265 to 33'^5 tons. 



These are illuminating figures which deserve 

 consideration and show plainly the development 

 of the by-product industry up to the commence- 

 ment of the war period. 



In addition to supplying home demands for 

 ammonia nitrogen, there was an average yearly 



• " Ministry of Munitions of War. Munitions Inventions Department. 

 Nitrojen Products Committee. Final Report." Pp. ¥{ + 357. (London: 

 H.M Stationery Office, 1919.) Cmd. 482. Price 4J. ne'. Se<; also Nati;re, 

 Janij.iry az and 29. 



NO. 2633, VOL. 105] 



export of ammonia, ammonia salts, and products 

 made therefrom during the years 191 1 to 1913 

 equivalent to 82 per cent, of the total home pro- 

 duction. This would have been more than suffi- 

 cient to provide the nitrate and nitric nitrogen 

 required for all purposes had the means of con- 

 version been available, which they were not, so 

 that we were dependent on imported nitrates for 

 various purposes, including agriculture, the manu- 

 facture of sulphuric acid, nitric acid, explosives, 

 and other products. 



Passing on to the war period, estimates for the 

 year 191 7 indicate a by-product ammonia increase 

 of 130 per cent, in the United States, 27 per cent, 

 in Germany, and only 6 per cent, in the United 

 Kingdom ; but Japan has in the meantime taken a 

 considerable step forward and increased her output 

 more than sixfold — from 8000 tons in 191 3 to 50,000 

 tons in 1917. The production of sulphate from 

 coke-ovens in the United States had increased by 

 191 6 to 83 per cent, of the total output, and in 

 the United Kingdom to more than 36 per cent. 

 of the total. Even during 1915 and 1916 con- 

 siderably more than half our production of 

 ammonia nitrogen was exported, and we were 

 using large quantities of imported nitrate, all of 

 which might be produced economically by 

 ammonia oxidation or by synthetic processes, 

 details of which are fully discussed in the report. 

 We have now arrived at the stage where synthetic 

 manufacture begins to complicate the ammonia 

 problem and the economics of the various pro- 

 cesses require the closest attention. 



With regard to post-war conditions, it is certain 

 that agricultural demands will be much greater 

 than formerly : many lessons were learnt during 

 the war, not the least being that of the need for in- 

 creased food production at home. The consump- 

 tion of combined nitrogen practically doubled 

 during the ten years preceding the war, and there 

 is little doubt that the increase will continue, 

 nitrogenous fertilisers being more and more in 

 demand, especially now that much more land is 

 under cultivation than in pre-war days ; in fact, 

 ' our own agricultural demand for fixed nitrogen 

 j in the form of sulphate of ammonia and nitrates 

 I was more than doubled during the war period 

 I only. Moreover, nitric nitrogen will be needed 

 j in increased quantities owing to the extension of 

 I chemical manufactures, such as dyes and drugs, 

 which hitherto have been too much neglected ; 

 and with this will be involved the oxidation of 

 by-product ammonia. 



It would appear likely that the world's produc- 

 tive capacity should now be able to provide some 

 30 to 40 per cent, more combined nitrogen than 

 in 1914, and this does not appear to be greater 

 than would have been the case under normal con- 

 ditions had the ordinary rate of growth in con- 

 sumption in the pre-war period been maintained 

 during the four years under consideration. 



Now, if food production in this country is t<> 



